The present invention relates to a vehicle door, and in particular to an apparatus and method for locating and fastening a door latch within such a door.
A typical vehicle door comprises an inner skin having an aperture and an outer skin. The aperture is provided to allow a door latch mechanism to be mounted directly onto a locally reinforced fixing area on the inner skin. A strengthening structure, such as side impact bar, may be fixed to the inner skin. The outer skin has little impact strength compared with the inner skin. During assembly of the door, the aperture allows the latch mechanism to be appropriately positioned within the door by an assembly worker or machine, prior to rigid fixing of the latch mechanism to the inner door skin, usually by three or so screws.
The impact strength of vehicle doors during both head on and side collisions is of paramount importance. While traditional doors with impact bars fixed to an inner door skin provide improved protection for vehicle passengers, their performance is limited by the strength of the inner door skin. A new type of vehicle door has been proposed, such as in PCT Application WO 01/23201 A1, where the strength of the door is principally provided by an inner structural member typically comprising a bar type frame with one or more cross members. Part of the frame may have a generally “U-shaped” cross section to provide runner means for mounting a retractable glass window. Such doors preferably have a thin continuous inner skin to provide a seal, but this is insufficiently strong or stiff to support the loads required for a latch mounting. Hence, in such doors it is necessary to attach the door latch directly to the structural member.
During assembly, it is necessary to position the latch mechanism, albeit non rigidly, such that when the inner door skin has been fixed to the structural member and outer door skin has been positioned ready for fixing to the structural member, the latch mechanism is maintained in a position which allows a fixing member to be inserted through holes in the outer door skin and strengthening structure and engage a thread in the lock mechanism, but equally allows the latch position to be controlled by the fixing member when it is tightened. This presents a problem as the latch mechanism cannot be held in position by an assembly worker or machine during assembly, unless the inner skin is fitted after the latch mechanism. This is disadvantageous as it requires extra fixing means and in particular as it is often necessary to verify the fixing torque of the latch after assembly of other components since this is a safety critical item.